Recovery of three types of gold in unconsolidated Pleistocene and Holocene alluvium of the Snake River drainage, southeastern Idaho

1988 ◽  
Author(s):  
G.A. Desborough ◽  
W.H. Raymond ◽  
R.P. Christian
Keyword(s):  
Snake River ◽  
River Drainage

Age of the Last Major Scabland Flood of the Columbia Plateau in Eastern Washington

1978 ◽  
Vol 10 (2) ◽  
pp. 171-180 ◽  
Author(s):  
Donal R. Mullineaux ◽  
Ray E. Wilcox ◽  
Walter F. Ebaugh ◽  
Roald Fryxell ◽  
Meyer Rubin
Keyword(s):  
Rocky Mountains ◽  
Columbia River ◽  
Radiocarbon Date ◽  
Snake River ◽  
River Drainage ◽  
Northern Rocky Mountains ◽  
Columbia Plateau ◽  
Northwestern Margin ◽  
Eastern Washington ◽  
Mount St Helens

Pumice layers of set S from Mount St. Helens can be correlated with certain ash beds associated with young flood deposits of the channeled scabland. The correlation points to an age of about 13,000 14C yr B.P. for the last major flood to have crossed the scabland. Until recently, the last major episode of flooding was thought to be closer to 20,000 yr B.P., an age inferred chiefly from the relation of the flood to glacial events of the northern Rocky Mountains. Several investigations within the last few years have suggested that the last major flood occurred well after 20,000 yr B.P. Tentative correlations of ash beds of the scabland with set S pumice layers, the relations of flood and glacial events along the northwestern margin of the Columbia Plateau, and a radiocarbon date from the Snake River drainage southeast of the plateau all indicate an age much younger than 20,000 yr. The postulated age of about 13,000 yr B.P. is further supported by a radiocarbon date in the Columbia River valley downstream from the scabland tract. Basal peat from a bog on the Portland delta of Bretz, which is a downvalley deposit of the last major scabland flood, has been dated as 13,080 ± 300 yr B.P. (W-3404).

Dammed If You Don’t, But What If You Do? Breaching the Lower Snake River Dams in Washington State

2020 ◽  
Vol 4 (1) ◽  
pp. 1-12
Author(s):  
Elizabeth C. Lopardo ◽  
Clare M. Ryan
Keyword(s):  
Policy Process ◽  
Food Source ◽  
Washington State ◽  
Federal Agencies ◽  
Snake River ◽  
Environmental Groups ◽  
Steep Decline ◽  
Mitigation Techniques ◽  
Economic Analyses

Four dams on the lower Snake River in Washington State generate hydropower and allow for regional agriculture and barge shipping to Portland OR. However, the dams impede the migration of local salmon populations (Oncorhynchus spp.), which are in steep decline, and drastically impact the populations of salmon and orca whales, for whom salmon are a primary food source. For years, environmental groups have argued for breaching the dams; other interests counter that the dams are too critical to the economy of the region to lose; and federal agencies assert that the dams can remain and salmon populations will recover with mitigation techniques. Scientific and economic analyses, litigation, and elected officials’ efforts have not been able to move the issue towards a solution. Readers will examine the interests of primary actors in the issue, how they influence the policy process, the role of scientific and economic analyses, and possible approaches for resolving the issue.

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